4. You should now hear your music through your Bluetooth / USB / Firewire device, but without the enhancements provided by my software. My app doesn't know yet that you want it to activate for your new device, so it will remain in sleep mode by default.

5. Click on the headphone menubar icon in the top right corner of your screen, then select "Configure USB, Bluetooth & Firewire".

6. You should now see a window like this:

7. Your new device should be in the bottom list. Drag it from the bottom list into the top list.

8. Click "Save". The app will now re-initialize and start to use your new device. From now on, the software will always activate automatically whenever you reconnect these USB or Bluetooth headphones later.

BTW, if you don't want the software to activate for your Mac's built-in headphone jack and you want to use it exclusively with a Bluetooth / USB / Firewire device, then you can drag "Built-in Headphone Jack" from the top into the bottom list to de-activate the normal headphone detection.

And if you totally screw up the device configuration and nothing works anymore.. you can always reset it by typing "defaults delete me.hajo.Hajo-Headphone-Enhancer DevicePriorities" into a terminal and then restarting your Mac.